Alter Table New Column And Update

Hi

for MS SQL 2000/2005

I am having a table (an old database, not mine) with char value for the column [localisation]

Users
[name] [nvarchar] (100) NOT NULL ,
[localisation] [nvarchar] (100)NULL

Now i have created a table [Localisation]

Localisation
[id_Localisation] [int] NOT NULL,
[localisation] [nvarchar] (100) NOT NULL

I am adding a new column to Users

ALTER TABLE [Users] ADD
[id_Localisation] int NULL

and I want to update the Column [Users].[id_Localisation] before to drop the column [Users].[Localisation]

something like

UPDATE [Users] SET id_Localisation = (SELECT Localisation.id_Localisation
FROM Localisation FULL OUTER JOIN
Users ON Localisation.Localisation = Users.Localisation)

Users.Localisation can have a NULL value (then no id_localisation return)

but it doesnt work because it returns > 1 row

thank you

how can I do it ?